Hologram autofocusing plays a crucial role in the automatic detection of reconstruction distance, especially in the event of tracking a dynamic object at focus or the presence of system disturbances caused by thermal or mechanical disturbances. An image quality metric evaluated based on the distribution of its eigenvalues is compared in function of the reconstruction distance to identify the location of the focal plane. The proposed automatic focal plane detection algorithm is capable of working with amplitude objects, phase objects, and mixed type objects.

The accuracy of particle detection and size estimation is limited by the physical size of the digital sensor used to record the hologram in a digital in-line holographic imaging system.  We proposes a method utilize the autoregressive (AR) interpolation of the hologram to increase pixel density and, effectively, the quality of hologram reconstruction.